The invention relates to a method of controlling the partial pressure of at least one substance or mixture of substances in simultaneously liquid and solid phase.
The invention relates in particular to so called liquid phase epitaxy techniques which serve to produce semiconductor components.
In one such method, a so called epitaxy boat has a chamber wherein for example, there is a depression, which contains a subtance or mixture of substances in the form of a so called growth substrate. The growth substrate is covered by a displaceable lid during a heating phase necessary during manufacture, the lid having a so called epitaxial growth melt in a recess. After the heating phase the lid 4 is displaced such that the epitaxial growth melt is located above the growth substrate so that a doped semiconductor layer can grow for example.
This method has the disadvantage that a proportion of the substance or mixture of substances is vapourised during the heating phase such that the growth substrate is provided with a flawed surface. This thermal damage may produce faulty semiconductor components.
In order to avoid this thermal damage it was proposed that a recess should be arranged in the lid this recess accomodating a body for example a so called covering substrate which has a similar chemical composition to the epitaxial growth substrate. Thermal damage to the surface always recurs in a method of this type and makes it impossible to produce reliable semiconductor components for example.